Longitudinal assessment of SARS-CoV-2 IgG seroconversionamong front-line healthcare workers during the first wave of the Covid-19 pandemic at a tertiary-care hospital in Chile
Journal
BMC Infectious Diseases
ISSN
1471-2334
Date Issued
2021
Author(s)
Macarena R. Vial
Maria Spencer-Sandino
Anne Peters
Claudia Calderon
Alicia Anderson
Type
Resource Types::text::journal::journal article
URL Institutional Repository
Abstract
<jats:title>Abstract</jats:title><jats:sec>
<jats:title>Background</jats:title>
<jats:p>Healthcare workers (HCWs) are at high risk of exposure to SARS-CoV-2. Cross-sectional studies have provided variable rates of seroprevalence in HCWs. Longitudinal assessments of the serological response to Covid-19 among HCWs are crucial to understanding the risk of infection and changes in antibody titers over time. We aimed to investigate seroprevalence and risk factors associated with seroconversion in a prospective cohort of HCWs during the peak of the first wave of the Covid-19 pandemic.</jats:p>
</jats:sec><jats:sec>
<jats:title>Methods</jats:title>
<jats:p>We conducted a longitudinal study among 446 front-line HCWsin a tertiary-care hospital in Chile from April to July 2020. IgG was determined monthly using two different ELISAs in serum samples of HCWs, during the three-month period. In each visit, demographic data, symptoms, risk factors, and exposure risks were also assessed.</jats:p>
</jats:sec><jats:sec>
<jats:title>Results</jats:title>
<jats:p>The overall seroprevalence at the end of the study period was 24% (95% CI20.2–28.3), with 43% of seropositive HCWs reporting no prior symptoms. Seroconversion rates significantly differed over the study period, from 2.1% to as high as 8.8% at the peak of the epidemic. There were no statistically significant differences observed between HCWs in direct clinical care of patients with Covid-19 and those working in low risk areas. Antibody titers appeared to wane over time.</jats:p>
</jats:sec><jats:sec>
<jats:title>Conclusions</jats:title>
<jats:p>HCWs were severely affected with a high rate of seroconversion that appeared to mirror the local epidemiological situation. A significant amount of participants underwent an asymptomatic infection, highlighting the need for improved surveillance policies. Antibody titers appear to wane over time; further studies to understand this finding’s impact on the risk of reinfection are warranted.</jats:p>
</jats:sec>
<jats:title>Background</jats:title>
<jats:p>Healthcare workers (HCWs) are at high risk of exposure to SARS-CoV-2. Cross-sectional studies have provided variable rates of seroprevalence in HCWs. Longitudinal assessments of the serological response to Covid-19 among HCWs are crucial to understanding the risk of infection and changes in antibody titers over time. We aimed to investigate seroprevalence and risk factors associated with seroconversion in a prospective cohort of HCWs during the peak of the first wave of the Covid-19 pandemic.</jats:p>
</jats:sec><jats:sec>
<jats:title>Methods</jats:title>
<jats:p>We conducted a longitudinal study among 446 front-line HCWsin a tertiary-care hospital in Chile from April to July 2020. IgG was determined monthly using two different ELISAs in serum samples of HCWs, during the three-month period. In each visit, demographic data, symptoms, risk factors, and exposure risks were also assessed.</jats:p>
</jats:sec><jats:sec>
<jats:title>Results</jats:title>
<jats:p>The overall seroprevalence at the end of the study period was 24% (95% CI20.2–28.3), with 43% of seropositive HCWs reporting no prior symptoms. Seroconversion rates significantly differed over the study period, from 2.1% to as high as 8.8% at the peak of the epidemic. There were no statistically significant differences observed between HCWs in direct clinical care of patients with Covid-19 and those working in low risk areas. Antibody titers appeared to wane over time.</jats:p>
</jats:sec><jats:sec>
<jats:title>Conclusions</jats:title>
<jats:p>HCWs were severely affected with a high rate of seroconversion that appeared to mirror the local epidemiological situation. A significant amount of participants underwent an asymptomatic infection, highlighting the need for improved surveillance policies. Antibody titers appear to wane over time; further studies to understand this finding’s impact on the risk of reinfection are warranted.</jats:p>
</jats:sec>
Cite this document
Iruretagoyena, M., Vial, M. R., Spencer-Sandino, M., Gaete, P., Peters, A., Delgado, I., Perez, I., Calderon, C., Porte, L., Legarraga, P., Anderson, A., Aguilera, X., Vial, P., Weitzel, T., & Munita, J. M. (2021). Longitudinal assessment of SARS-CoV-2 IgG seroconversionamong front-line healthcare workers during the first wave of the Covid-19 pandemic at a tertiary-care hospital in Chile. BMC Infectious Diseases, 21(1), 478. https://doi.org/10.1186/s12879-021-06208-2
Subjects
covid-19
;
sars-cov-2
;
seroprevalence
;
seroconversion
;
healthcare workers
;
adult
;
aged
;
antibodies, viral
;
chile
;
cohort studies
;
covid-19
;
covid-19 serological testing
;
enzyme-linked immunosorbent assay
;
female
;
health personnel
;
humans
;
immunoglobulin g
;
longitudinal studies
;
male
;
middle aged
;
prospective studies
;
sars-cov-2
;
seroconversion
;
seroepidemiologic studies
;
tertiary care centers
;
immunoglobulin g
;
sars-cov-2 antibody
;
immunoglobulin g
;
virus antibody
;
adult
;
aged
;
antibody titer
;
article
;
asymptomatic coronavirus disease 2019
;
blood sampling
;
chile
;
cohort analysis
;
controlled study
;
coronavirus disease 2019
;
demography
;
disease surveillance
;
enzyme linked immunosorbent assay
;
female
;
health care personnel
;
high risk population
;
human
;
infection risk
;
longitudinal study
;
major clinical study
;
male
;
occupational exposure
;
occupational hazard
;
pandemic
;
prospective study
;
reinfection
;
risk factor
;
seroconversion
;
seroprevalence
;
symptom
;
tertiary care center
;
trend study
;
blood
;
diagnosis
;
epidemiology
;
health care personnel
;
immunology
;
middle aged
;
procedures
;
seroepidemiology
;
tertiary care center